a constant force Fa of a magnitude 82.0 N ....?

Question

a constant force Fa of a magnitude 82.0 N is applied to a 3.00kg shoe box at an angle phi = 53.0 degree, causing the box to move up in a frictionless ramp at constant speed. How much work is done on the box by Fa when the box has moved through vertical distance h= 0.150m?

Answer 1

we have
A1 = F*s = F * h/ sin phi
A2 = -P*h
A = A1 + A2 = h( F/sin phi - mg ) = 10.9 J

Answer 2

[.15 / sin(53)]*82 = answer in units joule

The mass is irrelevant since the definition of work, W, for a constant force is W = F*d, where F is the magnitude of the constant force and d is the displacement. In this problem the displacement is the hypotenuse of the right triangle of the ramp.

(By the way, the other guy's answer is incorrect because he takes in account the work done by gravity which is not what the question asks. It only asks what the work Fa does on the box.)